1. Field of the Invention
The invention concerns a network for data transmission with modules linked together for data exchange and hub switches, each with several terminals and assigned and/or integrated memory array, with each hub switch connecting its terminals in pairs while disconnecting from all other terminals and/or temporarily storing the data packets forwarded via the terminals separately and only forwarding them to the respective address terminal when it is available for data reception and/or can be disconnected.
2. The Prior Art
These types of networks are known in principle in the field of communication networks, cf., for example, the U.S. Pat. Nos. 5,544,163, 5,781,530, and 5,790,786.
However, this technology has not yet gained favor in the control of industrial processes.
Rather, in typical process controls, the modules of the control are linked together via a bus, whereby it is provided that the individual modules transmit the data received by them, which is to be forwarded to other modules, at arbitrary times, determined without regularity. The data exchange can, however, only function if the data of one single module at a time is transmitted on the bus. If two or more data modules transmit their data simultaneously, each of these data modules immediately ends its data transmission and repeats the respective data transmission after a period of time determined by random generation. In this way, the previously mentioned data modules can, as a rule, be prevented by probability from again simultaneously attempting to transmit. It is also provided in current systems that a data module only begins to transmit if the bus is idle, i.e. no data transmission of another data module is detectable. In this way, it is ensured that a data transmission initiated by a data module cannot be interrupted during the transmission by another data module beginning to transmit. In widespread process controls, colliding data transmissions occur comparatively frequently, with the consequence that the data exchange can be delayed significantly and/or to such a degree that an optimal control of the respective process is no longer possible and/or is no longer possible with the desired rapidity.